Lens-free microscope with smart phone technology
The first lens-free microscope can be used for high-throughput 3-D tissue imaging—an important need in the study of disease. It works by using a laser or light-emitting-diode to illuminate a tissue or blood sample that has been placed on a slide and inserted into the device. A sensor array on a microchip—the same type of chip that is used in digital cameras, including cellphone cameras—captures and records the pattern of shadows created by the sample.
The device processes these patterns as a series of holograms, forming 3-D images of the specimen and giving medical personnel a virtual depth-of-field view. An algorithm color codes the reconstructed images, making the contrasts in the samples more apparent than they would be in the holograms and making any abnormalities easier to detect.
In a blind test, a board-certified pathologist analyzed sets of specimen images that had been created by the lens-free technology and by conventional microscopes. The pathologist’s diagnoses using the lens-free microscopic images proved accurate 99 percent of the time.
Another benefit of the lens-free device is that it produces images that are several hundred times larger in area, or field of view, than those captured by conventional bright-field optical microscopes, which makes it possible to process specimens more quickly.
While mobile health care has expanded rapidly with the growth of consumer electronics—cellphones in particular—pathology is still, by and large, constrained to advanced clinical laboratory settings. Accompanied by advances in its graphical user interface, this platform could scale up for use in clinical, biomedical, scientific, educational and citizen-science applications, among others.